From: Jens Wiklander <jens.wiklander@linaro.org>
To: Julien Grall <julien@xen.org>
Cc: xen-devel@lists.xenproject.org, patches@linaro.org,
Stefano Stabellini <sstabellini@kernel.org>,
Bertrand Marquis <bertrand.marquis@arm.com>,
Michal Orzel <michal.orzel@amd.com>,
Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
Subject: Re: [XEN PATCH v3 5/5] xen/arm: ffa: support notification
Date: Mon, 29 Apr 2024 11:55:34 +0200 [thread overview]
Message-ID: <CAHUa44H+ZieqRSHEigziZVRiYus_nayL=2nooZPj8bkRcNTvJg@mail.gmail.com> (raw)
In-Reply-To: <807e4e70-f3b2-4b40-9004-d55bd9407bbf@xen.org>
Hi Julien,
On Fri, Apr 26, 2024 at 7:58 PM Julien Grall <julien@xen.org> wrote:
>
> Hi Jens,
>
> On 26/04/2024 09:47, Jens Wiklander wrote:
> > +static void notif_irq_enable(void *info)
> > +{
> > + struct notif_irq_info *irq_info = info;
> > +
> > + irq_info->ret = setup_irq(irq_info->irq, 0, irq_info->action);
> In v2, you were using request_irq(). But now you seem to be open-coding
> it. Can you explain why?
It's because request_irq() does a memory allocation that can't be done
in interrupt context.
>
> > + if ( irq_info->ret )
> > + printk(XENLOG_ERR "ffa: request_irq irq %u failed: error %d\n",
> > + irq_info->irq, irq_info->ret);
> > +}
> > +
> > +void ffa_notif_init(void)
> > +{
> > + const struct arm_smccc_1_2_regs arg = {
> > + .a0 = FFA_FEATURES,
> > + .a1 = FFA_FEATURE_SCHEDULE_RECV_INTR,
> > + };
> > + struct notif_irq_info irq_info = { };
> > + struct arm_smccc_1_2_regs resp;
> > + unsigned int cpu;
> > +
> > + arm_smccc_1_2_smc(&arg, &resp);
> > + if ( resp.a0 != FFA_SUCCESS_32 )
> > + return;
> > +
> > + irq_info.irq = resp.a2;
> > + if ( irq_info.irq < GIC_SGI_STATIC_MAX || irq_info.irq >= NR_GIC_SGI )
> > + {
> > + printk(XENLOG_ERR "ffa: notification initialization failed: conflicting SGI %u\n",
> > + irq_info.irq);
> > + return;
> > + }
> > +
> > + /*
> > + * SGIs are per-CPU so we must enable the IRQ on each CPU. We use an
> > + * IPI to call notif_irq_enable() on each CPU including the current
> > + * CPU. The struct irqaction is preallocated since we can't allocate
> > + * memory while in interrupt context.
> > + */
> > + for_each_online_cpu(cpu)
> Even though we currently don't support CPU hotplug, you want to add a
> CPU Notifier to also register the IRQ when a CPU is onlined
> ffa_notif_init().
>
> For an example, see time.c. We may also want to consider to enable TEE
> in presmp_initcalls() so we don't need to have a for_each_online_cpu().
I was considering that too. I'll update the code.
Thanks,
Jens
next prev parent reply other threads:[~2024-04-29 9:56 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 8:47 [XEN PATCH v3 0/5] FF-A notifications Jens Wiklander
2024-04-26 8:47 ` [XEN PATCH v3 1/5] xen/arm: ffa: refactor ffa_handle_call() Jens Wiklander
2024-04-26 8:47 ` [XEN PATCH v3 2/5] xen/arm: ffa: use ACCESS_ONCE() Jens Wiklander
2024-04-26 8:47 ` [XEN PATCH v3 3/5] xen/arm: ffa: simplify ffa_handle_mem_share() Jens Wiklander
2024-04-26 8:47 ` [XEN PATCH v3 4/5] xen/arm: allow dynamically assigned SGI handlers Jens Wiklander
2024-04-26 8:47 ` [XEN PATCH v3 5/5] xen/arm: ffa: support notification Jens Wiklander
2024-04-26 9:20 ` Bertrand Marquis
2024-04-26 12:11 ` Jens Wiklander
2024-04-26 12:19 ` Bertrand Marquis
2024-04-26 12:32 ` Jens Wiklander
2024-04-26 12:41 ` Bertrand Marquis
2024-04-26 13:02 ` Jens Wiklander
2024-04-26 15:12 ` Bertrand Marquis
2024-04-26 18:31 ` Julien Grall
2024-04-26 17:58 ` Julien Grall
2024-04-29 9:55 ` Jens Wiklander [this message]
2024-04-26 19:07 ` Julien Grall
2024-04-29 7:20 ` Bertrand Marquis
2024-04-29 9:49 ` Jens Wiklander
2024-04-29 20:55 ` Julien Grall
2024-04-29 8:43 ` Jens Wiklander
2024-04-26 9:23 ` [XEN PATCH v3 0/5] FF-A notifications Bertrand Marquis
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